Light and medium class weapons are typically fired from weapon mounts that are themselves attached to a platform. Examples of light class weapons include the M2HB .50 caliber machine gun and the MK19 25 mm automatic grenade launcher. Examples of medium class weapons include a variety of 40×53 mm automatic grenade launchers, 25 mm chain guns, and 30×173 mm rapid-fire cannon. Examples of weapon mounts include crew-served weapon mounts such as rotorcraft door gunners and maritime weapon mounts, crew-served tripod mounts commonly used by dismounted soldiers (i.e., infantry, as opposed to serving as vehicle crew or riding in vehicles for transport), and a wide variety of fixed, flexible, skate-type, and other moveable vehicle weapon mounts. Examples of platforms include riverine craft such as the CCM and SOC-R, surface warfare craft such as the LCS, infantry fighting vehicles such as the M2 Bradley, multipurpose vehicles such as the HMMWV, main battle tanks such as the M1A2 Abrams, and rotorcraft such as the UH-1 Huey and UH-60 Blackhawk.
Traditional crew-served weapon mounts enable high situational awareness and high slew rates to reposition the weapon and engage multiple targets or provide suppressive fire. The use of snipers, ambushes, sneak attacks, and guerrilla tactics has increased in recent years, with a transition to combat and law enforcement activities in and around areas with populations of uninvolved civilians and non-combatants. In response, military and law enforcement leaders have emphasized the use of sensor systems, unmanned systems, and increased situational awareness of manned platforms to increase operational effectiveness while simultaneously reducing allied and civilian casualties as well as reducing collateral damage. Because of these operational goals and the heightened value of situational awareness and tactical flexibility, crew-served weapon mounts continue to serve our warfighters in the modern battlefield.
Crew-served weapon mounts, as well as other types of weapon mounts, suffer from systematic inaccuracies, as well as motion-induced, target tracking, and operator-specific inaccuracies. Crew-served weapon mounts in many operational scenarios also suffer from the risk of exhausting a magazine before the weapon is effectively brought to bear on a target when engaging under suboptimal conditions. What is needed are stabilization subsystem architectures, processing, and control methods that can effectively eliminate the largest inaccuracies that contribute to angular spread of crew-mounted weapons and other sensor and weapon mounts in a compact and cost-effective manner.
Numerous industry and government developers have designed and implemented various stabilization methods and systems for weapon and sensor mounts, wherein a stabilization subsystem is used to fix the position of a weapon (or camera) once aimed at a target using mechanical means. For the vast majority of these implementations, the stabilization subsystem fixes the position through physical locking mechanisms or gyroscopic spinning masses. Note that for the purposes of this discussion, an electromagnet-based locking mechanism is considered to be an equivalent to a mechanical locking mechanism, as the net purpose of any one of these mechanisms is to force the weapon to maintain its aim point by preventing it from aiming in another direction by means of mechanical (gyroscopic, electromotive, etc.) resistance to movement.
An example of the mechanical based stabilization means are the Mk49 (ROSAM) and Mk50 (Protector) remote weapon systems used by the United States Navy. Both of these systems use gyroscopes to measure the motion of the host platform and command a mechanical drive train to counteract the measured motion so that the weapon maintains the same aiming vector. Both of these systems also have an auxiliary mode of operation, wherein an operator can mechanically disengage the drive train so that he or she can manually slew and fire the weapon. Neither of these, or any other systems, allow the operator to switch from manual aiming to stabilized mode without physically disengaging the drive train nor do they allow an operator to locally adjust or “fine tune” an existing aim point at the weapon once stabilization is underway.
According to some researchers, an alternative method of weapon control is employed wherein electrical actuators control the weapon mount exclusively. A typical example is the remote turret weapon mounts commonly used on ground vehicles throughout U.S. and allied forces, covering a range of armaments from personal small arms through heavy cannon. In these systems, there is limited capability for a crewman to physically operate the weapon mount, as ballistic correction and stabilization benefits are provided only during remote operation. Even when crew operation is permitted, there is no ready availability of a true free-gunning mode, as the weapons have significant mechanical resistance due to gear trains and/or other coupled drive train elements. These must either be overcome physically by the crewman or be disabled with a specific mechanical procedure requiring time, training, and often risk to an operator who is typically required to move to an exposed position to perform the procedure. Furthermore, many small platforms have limited seating for crew and or mounted infantry to participate in a given mission. Converting a crew-served weapon station into a remote weapon station often removes one physical crew position that would have previously been available for personnel.
All of these attempts to develop and implement a weapon stabilization subsystem eliminate one or more of the critical advantages of crew-served weapon mounts. What is needed is a stabilization subsystem that preserves the intrinsic situational awareness, high slew rate, and personnel capacity of crew-served weapons, but still provides for accurate, precise, and effective engagement of targets.